The present invention relates to apparatus for cooling panels, especially panels which consist of sheet metal. More particularly, the invention relates to improvements in apparatus of the type wherein successive panels must advance through a channel whose width slightly exceeds the width of a panel and whose height is only slightly more than the thickness of the panel therein.
It is already known to provide a panel cooling apparatus with means defining a relatively narrow channel whose height does not appreciably exceed the thickness of the panels and which is immersed in a vessel. A continuous stream of water or another coolant is conveyed from the inlet toward the outlet of the channel so that the coolant contacts both sides of the panel or panels in the channel. The means for advancing a panel through the channel comprises pairs of rollers which engage the panel from above and from below. The rollers are mounted in the vessel and extend through the top and bottom walls of the structure which defines the channel. An apparatus of such type is disclosed, for example, in German Offenlegungsschrift No. 2,414,445. The purpose of the apparatus is to effect uniform cooling of both sides of the panel which is caused to advance through the channel. Such apparatus constitutes an improvement over earlier apparatus which utilize means for spraying water against both sides of a panel or plate consisting of sheet metal or the like. The cooling action of these earlier apparatus is not entirely satisfactory because the droplets of water which are propelled against the underside of the panel rebound and immediately descend by gravity. On the other hand, the droplets which are sprayed onto the upper side of the panel remain on the panel to form thereon a pool or stream which flows toward and beyond the marginal portions of the panel to produce an additional cooling action. In other words, the cooling action of water sprays upon the upper side is much more pronounced than the cooling action at the underside of the panel. Reference may be had to German Pat. Nos. 1,508,386 and 2,245,390 which disclose such earlier types of cooling apparatus. The apparatus of German Pat. No. 1,508,386 uses rollers in the form of wheels with tires which permit the sprinkled-on water to flow laterally therebetween as well as in the longitudinal direction of the panel. German Pat. No. 2,245,390 discloses rollers with worm threads which also permit water to flow longitudinally of a moving panel as well as laterally and beyond the two marginal portions of the panel.
The apparatus which is disclosed in the aforementioned German Offenlegungsschrift No. 2,414,445 exhibits the drawback that it is difficult to seal the channel forming means at the two sides of the channel in such a way that the height of the channel can be altered, i.e., so as to allow for introduction of thicker or thinner panels. Moreover, the rollers in the channel offer a pronounced resistance to the flow of coolant in the longitudinal direction of the channel so that the admitted coolant must be injected at an elevated pressure with additional expenditures for energy and heavy duty pumps.